U.S. Pat. No. 6,082,324 granted to the same inventor discloses a rotary internal combustion engine, which is a rotary engine including eccentric blade rotors. More specifically, the rotary internal combustion engine disclosed in the above-mentioned US patent includes a compression cylinder, a combustion chamber and a power cylinder. The compression cylinder and the power cylinder are internally provided with a compression rotor and a power rotor, respectively, which are fixedly mounted on the same one rotary shaft. The compression rotor and the power rotor respectively have three blades. When the rotary shaft rotates, the compression rotor compresses air in the compression cylinder and pushes the compressed air into the combustion chamber, in which the compressed air is ignited and exploded to generate expanded high-temperature and high-pressure gas. The expanded gas is sent into the power cylinder to move the blades in the power cylinder and accordingly drives the rotary shaft to rotate. For the above-described rotary engine to operate in a smoother manner, the same inventor has further developed some related techniques, which have been granted U.S. Pat. No. 9,458,719 entitled “Rotor Assembly for Rotary Internal Combustion Engine”.
However, according to U.S. Pat. No. 9,458,719, the rotary engine disclosed has a combustion chamber arranged between an intake-compression chamber and an exhaust-power chamber, such that the intake-compression chamber is located at a distance from the exhaust-power chamber to result in a somewhat big volume of the entire rotary engine. Further, in the rotary engine disclosed in U.S. Pat. No. 9,458,719, with the combustion chamber being arranged between the intake-compression chamber and the exhaust-power chamber, cylinder walls of the intake-compression chamber and the exhaust-power chamber become two independent units without being directly connected to each other, and the torsional moment produced when rotor assemblies provided in the intake-compression chamber and the exhaust-power chamber operate in the cylinder walls must be borne by pins fixed on outer parts of the cylinder walls. Also, the two not-directly-connected intake-compression chamber and exhaust-power chamber increase the structural complexity of the whole rotary engine and the difficulty in arranging cooling water passages in the cylinder walls. It is therefore tried by the same inventor to further develop an improved rotary engine with axially directly connected compression and power cylinders that includes a compression cylinder, an intermediate cylinder wall and a power cylinder that are axially arranged and sequentially connected together, enabling easy, straight-through and effective cooling water passages arrangement in the rotary engine.